A hated teacher? - please do not take this personally teachers who are reading this! 
One of my DDs, who had problems with her eyesight and wore glasses, found reading very difficult indeed. Nowadays she would be classed as dyslexic and have lots of help forthcoming, but in those days there was nothing. There was a teacher at one primary school she attended who ridiculed and belittled her endlessly and destroyed her confidence. Neither my DD nor I can speak of this woman now without seething - and DD gets very distressed when she is mentioned. DD is a big outgoing personality and full if exuberance now, but still the memory rankles.
I remember one occasion when, at the age of about 10, she struggled her way through an entire (very easy) book and at home we all acknowledged her success with hugs and smiles. She came home from school the next day in tears as the she had told the teacher of her achievement and was told "Katy X has read dozens of books!" How to put a child down in one easy lesson!
I used to dread parents' evenings, not just with this teacher, but many others whose first comment whenever we entered the room is "She's not as bright as her older sister" - in the end I would just say "Is this relevant?" I sent them to different schools at secondary stage.
As a counter-balance, I had the same teacher for 2 years at the latter end of my primary education and I loved him unreservedly. Avuncular and tweed clad, with a pipe in his pocket, he was wonderful - Mr Farrell I salute you! And the skinny white-haired lady music teacher who told me I could sing and changed my entire life. Dear Miss Matthews.